The invention relates generally to multi-slab multichannel heat exchangers.
Heat exchangers are used in heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems. Multichannel heat exchangers generally include multichannel tubes for flowing refrigerant through the heat exchanger. Each multichannel tube may contain several individual flow channels. Fins may be positioned between the tubes to facilitate heat transfer between refrigerant contained within the tube flow channels and external air passing over the tubes. Multichannel heat exchangers may be used in small tonnage systems, such as residential systems, or in large tonnage systems, such as industrial chiller systems.
In general, heat exchangers transfer heat by circulating a refrigerant through a cycle of evaporation and condensation. The rate of heat transfer may be affected by the location of a multichannel tube within a heat exchanger. For example, in a heat exchanger containing horizontal tubes, the bottom tubes may receive less airflow than the top tubes, resulting in a lower rate of heat transfer between the bottom tubes and the environment. In a heat exchanger containing vertical tubes, the outer tubes may receive less airflow based on proximity to other equipment or an outer wall. Further, multichannel heat exchangers may be placed in multi-slab configurations to provide increased capacity within a small equipment footprint. For example, two slabs of heat exchanger tubes may be placed side-by-side. In a multi-slab configuration, the outer heat exchanger coils may receive more airflow, resulting in a higher rate of heat transfer between these tubes and the environment.